In an emerging new concept, freeze-dried plant cells (lettuce) expressing biopharmaceuticals (fused with transmucosal carriers) are protected in the stomach from acids/enzymes but are released to the circulatory or immune system when plant cell walls are digested by microbes that colonize the gut. Therapeutic proteins in lyophilized plant cells (in capsules) are stable >30 months at room temperature and maintain their folding, disulfide bonds, assembly and functionality.

Oral delivery of antigens or auto-antigens bio-encapsulated in plant cells:Several vaccine antigens (against Dengue, polio, malaria, tuberculosis, cholera, anthrax, plague, etc) or autoantigens (diabetes, hemophilia, etc) have been expressed in lettuce chloroplasts. Vaccine antigens bio-encapsulated in plant cells upon oral delivery after priming, conferred both mucosal and systemic immunity and protection against bacterial, viral or protozoan pathogens or toxin challenge. In recent studies supported by the Gates Foundation were done in collaboration with FDA and neutralization studies were evaluated by the CDC laboratories.